Fig. 2.

Hypothetical directed acyclic diagram of a COVID-19 inflammation causal path with risk factors, confounders and other covariates. Legend: Exposure = SARS-CoV-2 (E) (acute respiratory syndrome coronavirus 2); outcomes are H: hospitalisation (H = {regular ward, semi-intensive care, ICU}), and B: blood tests (B = {B1,…,BK}); Covariates are RF: risk factor (RF = {RF1,…,RF4A, RF4B,RF5}), SOC: single outcome covariate (SOC = {SOC1,…,SOC5}) and BOC: both outcomes confounder (BOC = {BOC1,BOC2}).